ION: Remove build result from git folder to build result folder [1/2]

PD#SWPL-150389

Problem:
Remove build result from git folder to build result folder --- libion

Solution:
support output folder in Makefile

Verify:
local

Signed-off-by: guoping.li <guoping.li@amlogic.com>
Change-Id: Icbad012f37172e10bfaa0accbc38eea66f0d51ec
diff --git a/Makefile b/Makefile
index 47e5fe4..bde5527 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,7 @@
 #
 ## makefile for libion and iontest
 #
+OUT_DIR ?= .
 LIBION_OBJ = ion.o IONmem.o
 CFLAGS += -I ./include/
 CFLAGS += -I ./kernel-headers/
@@ -15,14 +16,13 @@
 all: $(LIBION) $(IONTEST)
 
 %.o: %.c
-	$(CC) -c -fPIC  $(CFLAGS) $^ -o $@
+	$(CC) -c -fPIC  $(CFLAGS) $^ -o $(OUT_DIR)/$@
 
 $(LIBION): $(LIBION_OBJ)
-	$(CC) -shared  -Wl,-soname,$(LIBION) -fPIC $(CFLAGS) $^ -o $(LIBION)
+	$(CC) -shared  -Wl,-soname,$(LIBION) -fPIC $(CFLAGS) $(patsubst %, $(OUT_DIR)/%, $^) -o $(OUT_DIR)/$(LIBION)
 
 $(IONTEST): $(IONTEST_OBJ) $(LIBION)
-	$(CC) $^ $(CFLAGS)  -o $@
+	$(CC) $(CFLAGS) $(LDFLAGS) $(patsubst %, $(OUT_DIR)/%, $^) -o $(OUT_DIR)/$@
 
 clean:
-	rm -f $(LIBION_OBJ) $(LIBION) $(IONTEST_OBJ) $(IONTEST)
-
+	rm -f $(OUT_DIR)/$(LIBION_OBJ) $(OUT_DIR)/$(LIBION) $(OUT_DIR)/$(IONTEST_OBJ) $(OUT_DIR)/$(IONTEST)